RESUMEN
OBJECTIVES: Carotid artery reactivity (CAR%), involving carotid artery diameter responses to a cold pressor test (CPT), is a noninvasive measure of conduit artery function in humans. This study examined the impact of age and cardiovascular risk factors on the CAR% and the relationship between CAR% and coronary artery vasodilator responses to the CPT. METHODS: Ultrasound was used to measure resting and peak carotid artery diameters during the CPT, with CAR% being calculated as the relative change from baseline (%). We compared CAR% between young (nâ=â50, 24â±â3 years) and older participants (nâ=â44, 61â±â8 years), and subsequently assessed relationships between CAR% and traditional cardiovascular risk factors in 50 participants (44â±â21 years). Subsequently, we compared left anterior descending (LAD) artery velocity (using transthoracic Doppler) with carotid artery diameter (i.e. CAR%) during the CPT (nâ=â33, 37â±â17 years). RESULTS: A significantly larger CAR% was found in young versus older healthy participants (4.1â±â3.7 versus 1.8â±â2.6, Pâ<â0.001). Participants without cardiovascular risk factors demonstrated a higher CAR% than those with at least two risk factors (2.9â±â2.9 versus 0.5â±â2.9, Pâ=â0.019). Carotid artery diameter and LAD velocity increased during CPT (Pâ<â0.001). Carotid diameter and change in velocity correlated with LAD velocity (râ=â0.486 and 0.402, Pâ<â0.004 and 0.02, respectively). CONCLUSION: Older age and cardiovascular risk factors are related to lower CAR%, while CAR% shows good correlation with coronary artery responses to the CPT. Therefore, CAR% may represent a valuable technique to assess cardiovascular risk, while CAR% seems to reflect coronary artery vasodilator function.
Asunto(s)
Arterias Carótidas/fisiología , Vasos Coronarios/fisiología , Vasodilatación , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Velocidad del Flujo Sanguíneo , Enfermedades Cardiovasculares/fisiopatología , Arterias Carótidas/diagnóstico por imagen , Grosor Intima-Media Carotídeo , Frío , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Adulto JovenRESUMEN
We propose a novel ultrasound approach with the primary aim of establishing the temporal relationship of structure and function in athletes of varying sporting demographics. 92 male athletes were studied [Group IA, (low static-low dynamic) (n = 20); Group IC, (low static-high dynamic) (n = 25); Group IIIA, (high static-low dynamic) (n = 21); Group IIIC, (high static-high dynamic) (n = 26)]. Conventional echocardiography of both the left ventricles (LV) and right ventricles (RV) was undertaken. An assessment of simultaneous longitudinal strain and LV volume/RV area was provided. Data was presented as derived strain for % end diastolic volume/area. Athletes in group IC and IIIC had larger LV end diastolic volumes compared to athletes in groups IA and IIIA (50 ± 6 and 54 ± 8 ml/(m(2))(1.5) versus 42 ± 7 and 43 ± 2 ml/(m(2))(1.5) respectively). Group IIIC also had significantly larger mean wall thickness (MWT) compared to all groups. Athletes from group IIIC required greater longitudinal strain for any given % volume which correlated to MWT (r = 0.4, p < 0.0001). Findings were similar in the RV with the exception that group IIIC athletes required lower strain for any given % area. There are physiological differences between athletes with the largest LV and RV in athletes from group IIIC. These athletes also have greater resting longitudinal contribution to volume change in the LV which, in part, is related to an increased wall thickness. A lower longitudinal contribution to area change in the RV is also apparent in these athletes.